(1) Field of the Invention
The invention relates to the fabrication of integrated circuit devices, and more particularly, to a method and apparatus for the transportation of reticle boxes.
(2) Description of the Prior Art
In the creation of semiconductor devices, many interacting technical disciplines are required in order to produce semiconductor devices at a cost competitive price. While many of the disciplines address technologies that are exclusively associated with the creation of semiconductor devices, additional disciplines are required that act in support of semiconductor manufacturing facilities. While these additional disciplines may on the surface appear of a less deep-going technical nature, these disciplines are nevertheless fundamental to the successful operation of a semiconductor foundry.
One of the aspects of creating semiconductor devices is the making available of tool components and sub-components to the various processing stations and processing steps. It is well known in the art that photolithographic exposure of semiconductor surfaces is fundamentally important in the creation of semiconductor devices. One of the key components that is used during photolithographic exposures is the reticle, which contains the image of a pattern that must be exposed on an underlying surface. This reticle is detachable from the main tool in which the reticle is used, for instant a step-and-repeat exposure tool. The reason for this capability of being detached from the main tool is that the reticle must be readily interchangeable and must be available for other processing stations. This leads to the requirement that, once the reticle has been detached from a processing tool, this reticle must be safely and efficiently transported to the location where the reticle is required or to a storage location. In view of the expense incurred in creating the reticle, it is clear that this transportation must not cause any damage to the reticle while the reticle must during transportation be protected from outside influences to the maximum extent possible. Typically the reticle will be placed in a reticle container, which secures the reticle and which further protects the reticle. One additional step of protection is required where multiple reticles must be simultaneously transported, each reticle having being inserted into a reticle container. This transportation of multiple reticles is typically performed using a cart, commonly referred to as a reticle transportation cart. The common requirements that such a reticle transportation cart must meet are the following:    1. no static electricity must be generated during the process of transporting the reticles that are contained in the reticle containers (or boxes). This implies that the reticle containers cannot make physical contact with each other since such a contact would most likely result in a rubbing, frictional motion between the reticle containers, which is prone to create static electricity in the reticle containers that are in contact with each other.    2. the reticles must not be subjected to undue vibration, since vibration may result in damage to the reticle or to the images that are created on the surface of the reticle    3. the reticle cart must have Electro Static Discharge (ESD) protection to assure that no ESD will accumulate on the chart, which would further expose the reticle boxes and therefore the reticles to ESD    4. the reticle cart must provide adequate protection to the reticle boxes and by implication to the reticles
U.S. Pat. No. 5,782,356 (Hugg) shows a container for transporting reticles.
U.S. Pat. No. 5,390,785 (Garric et al.) shows another container for transporting reticles.
U.S. Pat. No. 5,320,225 (Kirkpatrick), U.S. Pat. No. 4,981,222 (Lee) and U.S. Pat. No. 6,196,001 (Tannous et al.) show related semiconductor part vessels and containers.